Winter is right around the corner, and if your windows are anything like mine, you will soon be having cold air drafting through them while they are closed. There are a few things that can be done to keep yourself warm and save on energy costs in the coming months.
Growing up in my parents house with old single pane windows, around October every year, my mom would put plastic up around the window. The difference was noticeable almost immediately. This is an inexpensive and fairly easy way to keep the cool air out and warm air in. Window Insulator Kits are available in just about every hardware and general store. The instructions in the kits do a good job of guiding you, and all that is needed is a hair dryer to shrink the plastic film to keep it airtight. It may, however, be best to keep the plastic off of windows or glass doors that need to be opened and closed frequently. Multiple videos can also be found online on how to put the plastic up; here is a good one that shows the process step by step.
Heavy blackout curtains are also a good option to provide an extra layer of insulation that keeps the heat in. While they are usually more pricey than the plastic mentioned above, they are available in a fairly large price range allowing you to find some that fit your needs while also adding some decoration to the room.
Cellular shades are by far the best insulation option if you are looking for a more traditional blind/shade window covering. You would want to get a double cell shade to provide an extra layer over the single cell option. They are also available in light filtering or blackout depending on how much light and heat you want entering the room. These can be purchased off the shelf or custom made depending on the size of your window, and again are available in a fairly large price range.
Another option is to caulk the window to seal any holes or cracks that may have formed in the frame allowing air to get in and out. Check out this video on how apply the caulk.